Prosecutors allege Manafort and his deputy Rick Gates illegally acted as unregistered foreign agents for Ukrainian political interests by hiring and directing lobbying work by the Democratic-leaning Podesta Group and a Republican competitor.

It is not clear what Podesta’s firm knew about Manafort’s ultimate client or the extent of his involvement when it performed lobbying work on behalf of the European Center for a Modern Ukraine between 2012 and 2014. Prosecutors allege the organization was a front for the Ukrainian government.

A person familiar with the Podesta Group, who spoke anonymously to preserve relationships with former colleagues, says Podesta resigned to avoid further enmeshing his firm and colleagues in controversy.